Can Young Blood Curb the Effects of Ageing?

There's a familiar cliché — dreaded by the veterans of any occupation -- that "it's time for new blood." Now it turns out there may be something to it. The blood of young mice injected into the streams of old mice seems to reverse some effects of ageing. We hear about the latest research and what it might mean for humans from Jocelyn Kaiser, staff writer for Science Magazine, and Ronald Kohanski, Deputy Director of the Division of Ageing Biology at the National Institute on Ageing, which is part of the National Institutes of Health.